Study of Chokeberry to Reduce Cardiovascular Disease Risk in Former Smokers

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More than 31% of Connecticut adults are former smokers, which may contribute to the high cardiovascular disease (CVD) risk in this state. Atherosclerosis, a hallmark of CVD, is a progressive life-long process. Chronic cigarette smoking increases atherosclerosis and CVD risk. While smoking cessation may lower CVD risk, former smokers still are at high CVD risk. The mechanisms by which smoking accelerates atherosclerosis formation are not fully understood. This knowledge gap prevents development of informed interventions to reduce CVD risk in former smokers.

Previous work suggests smoking increases oxidative stress and leads to elevated CVD risk. Former smokers also have decreased antioxidants and markers of vascular function in the circulation, suggesting that despite cessation, smoking has a lingering adverse effect on CVD protective mechanisms. Chokeberry (Aronia melanocarpa) is a native Connecticut plant rich in polyphenol antioxidants and is a promising intervention for reducing CVD risk in former smokers. Chokeberries have diverse polyphenols such as anthocyanins, proanthocyanidins, resveratrol, quercetin, and chlorogenic acid. Chokeberry consumption improves dyslipidemia, inhibits inflammation, and reduces oxidative stress in humans and animals, all of which could contribute to the prevention of CVD in former smokers. Therefore, our central hypothesis is that dietary chokeberry polyphenols reduce CVD risk in former smokers by improving lipid profiles and inhibiting inflammation and oxidative stress. Our long-term goal is to define the mechanisms by which polyphenol antioxidants mitigate CVD risk. The overall goal of this project is to conduct a randomized placebo-controlled clinical trial to evaluate the cardio-protective effects of dietary chokeberry polyphenols in former smokers.

Our objectives are to determine 1) the effect of chokeberry polyphenols on plasma cholesterol and triglyceride levels and on gene expression involved in cholesterol metabolism; 2) the extent to which chokeberry improves antioxidant and vascular function in former smokers; and 3) the association of bioavailability of chokeberry polyphenols to changes in biomarkers of CVD risk.

Successful completion of this work will result in improved understanding of the role of dietary berry polyphenols to regulate lipid metabolism, inflammation and oxidative stress. Thus, this study will be an important step to developing dietary recommendations for individuals predisposed to CVD risk, particularly former smokers.

Monocyte LDL receptor mRNA normalized to glyceraldehyde-3-phosphate dehydrogenase after chronic supplementation. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

LDL Receptor (LDLR) Protein [ Time Frame: Baseline, 12 weeks ]

Monocyte LDL receptor protein by Western blot, normalized to β-actin after chronic supplementation. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

Plasma Area Under the Curve of Chokeberry Polyphenols and Their Metabolites. [ Time Frame: 0, 0.5, 1, 2, 4, 6, 9, 12, and 24 hours following dose ]

Plasma area under the curve of chokeberry polyphenols and their metabolites. Measurement (time 0) began at study baseline. Not determined in chronic arms (Color-matched Rice Powder Pill or Chokeberry Extract Capsule).

Urinary Excretion of Polyphenols [ Time Frame: 0 to 24 h after consumption of extract ]

Urinary excretion of polyphenols, from 0 to 24 h after consumption of extract, area under the curve (AUC) in Chokeberry Extract Capsule (acute) arm only.

Adiponectin [ Time Frame: Baseline, 6 weeks, 12 weeks ]

Fasting plasma adiponectin after chronic consumption. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

Interleukin-1 Beta [ Time Frame: Baseline, 6 weeks, 12 weeks ]

Fasting plasma interleukin-1 beta after chronic consumption. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

Interleukin-6 [ Time Frame: Baseline, 6 weeks, 12 weeks ]

Fasting plasma interleukin-6 after chronic supplementation. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

Energy-adjusted intake based on 3-day dietary recalls, determined by the average of baseline and 12 weeks. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

Energy Intake [ Time Frame: Baseline, 12 weeks ]

Energy intake reported from 3-day dietary recalls at baseline and 12 weeks, determined by the average of baseline and 12 weeks. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

Energy-adjusted micronutrient intake from 3-day dietary recalls at baseline and 12 weeks. Values reported as the average of baseline and 12 weeks. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

Polyphenol Intake [ Time Frame: Baseline, 12 weeks ]

Energy-adjusted polyphenol intake assessed by 3-day dietary recalls at baseline and 12 weeks, values determined by average of baseline and 12 weeks. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

Energy-adjusted intake of dietary antioxidant capacity determined by 3-day dietary recalls at baseline and 12 weeks. Values reported as average of baseline and 12 weeks. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

Energy-adjusted Vitamin A Intake [ Time Frame: Baseline, 12 weeks ]

Energy-adjusted vitamin A intake from 3-day dietary recalls at baseline and 12 weeks. Values reported as the average of baseline and 12 weeks. Not determined in Chokeberry Extract Capsule (Acute) arm as this arm was a one-time dose.

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